Effect of successive application of various animal manures on the yield of crop plants and chemical property of soil

The effect of application of excrements on forage yields of Sorghum and Italian ryegrass and the physiological and chemical properties of the soil were examined. The results obtained were as follows: 1) A rate or 75 kgN/10a was equivalent to the rate of 14.3, 28.7, 1.9 and 8.6 t/10a of row cow, horse and pig feces and dried chicken feces applied, respectively. 2) Although these feces were applied for 13 years, forage yields of Sorghum and Italian ryegrass did not increase. The yields either remained on the same level or decreased slightly as application periods are long. 3) Forage yields of Sorghum and Italian ryegrass were strongly affected by the kind of feces. The highest yield was produced in plots applied horse feces in Sorghum. In Italian ryegrass, on the other hand, the highest yield was produced in plants applied chicken feces. 4) In plots where 25 kg/10a of cow, chicken and pig feces, which were the standard application Kyushu area, were applied for 13 years, early seeding growth was stunted and forage yields decreased in sorghum after the third year. 5) In plots applied cow feces, potassium in soil was high not only in the plow layer but also in the subsoil and large quantities of potassium percolated was found even in the soil below 9cm, plots applied horse feces had a high level of potassium, especially in the surface soil where 2meq/100g of potassium was found. Horse feces also has "shirasu" soil in it. The contents of total carbon, total nitrogen, nitrate nitrogen and the value of CEC was less than those in other feces, but the content of available nitrogen was greater. The chicken feces plot contained a little potassium, and there was little difference in the quantity of potassium between this area and the area used 25 kgN of cow and pig feces. The decomposition of chicken feces was very quick, so nitrate nitrogen went through the soil layer deeper than 60cm and with this, lime went deeper than 30 to 45cm